@mashton it does also matter what brake levers you have - Shimano have had a few different 'standards' over the years that are slightly different from the 'standards' that campag and sram have.
(not-so-)mini-Vs like a CX90 (with 90mm arms) won't be good with campag/sram but will work fine with newer shimano (mostly 10spd+). The slightly shorter CX84 (84 mm arms, similar to Tektro 926AL and Shimano) work well with all of them.
FWIW, I have CX90s running with 6700 levers and they're fine albeit slightly binary. I think the CX84 were put out specifically to play nice with SRAM/Campag (CX90 had too much mechanical advantage for them) as well as tone things down a bit for the Shimano crowd. Plus added rim clearance.
@mashton it does also matter what brake levers you have - Shimano have had a few different 'standards' over the years that are slightly different from the 'standards' that campag and sram have.
(not-so-)mini-Vs like a CX90 (with 90mm arms) won't be good with campag/sram but will work fine with newer shimano (mostly 10spd+). The slightly shorter CX84 (84 mm arms, similar to Tektro 926AL and Shimano) work well with all of them.